January 23, 1902] 



NA TURE 



I'll 



that we must make no use of the bisector of an angle or 

 of a line until we have shown how to draw the bisector. 

 Fancy anyone laying down the law for Clerk Maxwell 

 that he must make no investigation of the electromagnetic 

 theory of light until he has demonstrated the reality of 

 the ether ! By ignoring^ the restriction, Mr. Croome 

 -Smith is enabled to replace the usual proof of the Asses' 

 Bridge proposition by one much simpler. 



All the problems of Euclid (to bisect an angle, to draw 

 a perpendicular to a line from a point without it, to draw 

 a tangent to a circle, &c.) are kept by themselves in a 

 section at the end of the book. The author's proofs 

 leave nothing to be desired on the score of simplicity, and 

 his little book will be of much value to any committee 

 that may be formed by the Universities or the British 

 .Association for the purpose of providing an easy and 

 natural course of geometry for use in our schools. 



We cannot refrain from calling the author's attention 

 to the form of such a statement as (p. 31) : "A rhombus, 

 and therefore a square, are equilateral." This is fol- 

 lowed by one of similar arrangement ; and in line 12 

 from the end of p. viii, " is implied " should be " are 

 implied." 



OUR BOOK SHELF. 

 The Small Farm atid its Management. By James Long. 



Pp. xvii + 281. (London : Smith, Elder and Co., 



1901.) Price bs. 

 Mr. Long starts with the idea that it is very desirable 

 for the purpose of maintaining a vigorous rural popula- 

 tion that the number of small farms cultivated by their 

 owners should be considerably increased. Nearly every- 

 one will probably agree to this proposition. When, how- 

 ever, we learn the conditions needed for the success of 

 the small farmer, and which are plainly set forth by the 

 skilful writer of the present book, we become more and 

 more convinced that the extent to which successful 

 farming of this kind can be developed under present 

 conditions is very limited. 



Mr. Long tells us that for a successful twenty-acre 

 farm, third-class land must be refused at any price ; that 

 second-class land should only be occupied by highly 

 skilled men with sufficient capital ; and that first-class 

 land should, if possible, always be selected for such a 

 holding. The land must, further, be situated near a 

 railway, with easy access to a large consuming population. 

 Such land, Mr. Long frankly tells us, will generally be 

 found already occupied, and could not be purchased save 

 at a high price. His ideal farm is, further, to have one- 

 half of its area in permanent grass, and to possess an 

 acre of orchard. It must, of course, have a dwelling house 

 and farm buildings, with a suitable access to a road. 

 How can all these special conditions De provided e.'ccept 

 at a prohibitory cost ? 



When we pass to the details of the management which 

 is to result in a handsome profit to the owner, we discover 

 that he is supposed to be no mere agricultural labourer, 

 but to excel both in knowledge and judgment the average 

 farmers of the country. His farm of twenty acres is to 

 carry one horse, four cows, a breeding flock of ten ewes, 

 two sows and their offspring, eighty hens and forty 

 turkeys, and is to produce for sale twenty-four quarters of 

 oats, twelve tons of potatoes, and the fruit from an acre 

 of orchard. His four cows are to be chosen and 

 managed with such judgment and skill that they will 

 yield 3000 gallons of milk every year, a quantity far 

 above the average. His hens are to lay twice the number 

 of eggs usual in poultry yards. Everything on the farm 



NO. 1682, VOL. 65] 



is assumed to be first rate and thoroughly successful. 

 The result of this splendid management is to be a profit 

 of 120/. per annum. Years of drought, or other agri- 

 cultural disasters, are apparently not supposed to occur. 

 It will naturally be asked, if a profit of 120/. can be made 

 on twenty acres, why should not an annual profit of 

 1200/. be made on a farm of 200 acres worked on the 

 same lines ? And if such is the value of the land to the 

 occupier, at what price can it be purchased ? 



Whatever opinions we may form as to the possibility of 

 creating a system of small farms, or as to the prospects 

 of their profitable cultivation, we can form but one 

 opinion about Mr. Long's book. It is well done, and sup- 

 plies a large amount of information on a great variety of 

 subjects which cannot fail to be of value to all who are 

 seeking to make a profit out of a small holding. 



R. W. 



LHu'itre Perliere, Nacre et Perles. Par L. G. Seurat. 



("Encyclop. Scient. des Aide-Memoire"). Pp. 194. 



(Paris : Masson et Cie.) Price 2 fr. 50 c. 

 This is a useful little book of close on 200 pages and 

 a few illustrations, in which the author — whose name 

 was already known in connection with pearl oysters — 

 has brought together the leading facts in regard to the 

 molluscs, of both sea and fresh waters, producing pearl 

 and mother-of-pearl. The introduction shows that the 

 book has been written mainly in the interests of the 

 French nacre industries, which the author regards as of 

 great national importance. Although London is at 

 present the great market for pearl shell, we are told that 

 " La France possede, en effet, les plus vastes bancs 

 d'huitres perlieres et nacri^res qui soient au Monde, dans 

 ses colonies d'Oceanie," and the author evidently desires 

 to stimulate the exploitation and cultivation of the French 

 pearl industries at Tahiti and other Pacific stations. 

 But still, the descriptions of animals and fisheries have 

 been drawn from all parts of the world, and, in fact, 

 most attention is given to the oyster {Meleagrina fucata) 

 of Ceylon and British India on the well-known banks of 

 the Gulf of Manaar. 



M. Seurat points out on more than one page the gaps 

 in our knowledge of the nacre-forming molluscs, and 

 wisely insists upon the necessity of a thorough examin- 

 ation of the structure, life-history and habits of the 

 Meleagrinas before it is possible to establish a rational 

 regulation of the fisheries. The scope of the work may 

 be gauged by the following summary of the contents of 

 the chapters : .Anatomy and biology of the pearl oyster 

 and of other molluscs that produce pearls or nacre ; the 

 pearls, their position, structure, chemical composition 

 and experiments as to their production artificially ; the 

 fisheries both in the sea and also in the rivers of Europe 

 and America ; commerce and industries ; and, finally, 

 pearl-oyster cultivation. In his conclusion our author 

 sums up that 'Tostrciculture perlicre est une chose 

 possible, qui est susceptible de donner des resultats 

 pratiques," and draws a rosy picture of the prosperity 

 that would attend the lagoons of Tahiti under a rational 

 exploitation of this new industry. So may it be. 



V\nccs of Nature and Lessons from Science. By Caroline 

 A. Martineau. Pp. 160. (London : Sunday School 

 Association, 1901). Price is. net. 

 Miss Martine.vu describes clearly a number of simple 

 scientific facts, mainly concerning natural history subjects. 

 She thus assists the extension of a knowledge of nature 

 among those who are greatly in need of it. The pro- 

 minence given to Darwin's teachings — a large part of 

 the book being taken up with the elementary principles 

 of evolution — is a very commendable characteristic. The 

 spiritual lessons to be learnt from natural phenomena 

 may be "skipped" by readers who prefer to deal with 

 ethics apart from natural science. 



